http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49379
--- Comment #5 from Paul H. Hargrove <PHHargrove at lbl dot gov> 2011-06-29 04:20:13 UTC --- Created attachment 24629 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24629 Second (non Apple) reproducer for bug 49379 This attachment is a simple 3-file reproducer for this bug on x86-64/Linux (no Apple linker involved): As seen by Gary the -fno-tree-vectorize flag eliminates an alignment warning from the linker that is otherwise present at -O3 (or with explicit "-ftree-vectorize at -O1 and -O2): $ tar xfvj bug49379-2.tar.bz2 bug49379-2.h bug49379-2_aux.c bug49379-2_main.c $ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O3 bug49379-2_main.c bug49379-2_aux.c /usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccwZjyV0.o is smaller than 16 in /tmp/ccYSRWEX.o $ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O3 -fno-tree-vectorize bug49379-2_main.c bug49379-2_aux.c $ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O2 -ftree-vectorize bug49379-2_main.c bug49379-2_aux.c /usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccSN6r8r.o is smaller than 16 in /tmp/cc7JOniC.o $ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc -B/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc -O1 -ftree-vectorize bug49379-2_main.c bug49379-2_aux.c /usr/bin/ld: Warning: alignment 4 of symbol `flag' in /tmp/ccw0AZs5.o is smaller than 16 in /tmp/ccRVugJ6.o $ /tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc -v Using built-in specs. COLLECT_GCC=/tmp/gcc-4.7-20110625/host-x86_64-unknown-linux-gnu/gcc/xgcc Target: x86_64-unknown-linux-gnu Configured with: ./configure --enable-languages=c --with-mpc=/usr/common/ftg/gcc/common/ Thread model: posix gcc version 4.7.0 20110625 (experimental) (GCC) $ ld --version GNU ld version 2.17.50.0.6-14.el5 20061020 Copyright 2005 Free Software Foundation, Inc. This program is free software; you may redistribute it under the terms of the GNU General Public License. This program has absolutely no warranty. $ uname -a Linux tesla 2.6.18-194.17.1.el5 #1 SMP Wed Sep 29 12:09:22 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux $ cat /etc/redhat-release Scientific Linux SL release 5.5 (Boron)
